Mercury switch



Ndv. 21, 1933. c. HATAY 1,935,710

MERCURY SWITCH Filed Sept. 10, 1930 INVENTOR ATTORNEY Patented Nov. 21, 1933 PATENT OFFICE MERCURY SWITCH Charles Hatay, Berlin,

Germany, assignor to General Electric Company, a corporation of New York Application September 10,

1930, Serial No.

481,049, and in Germany September 18, 1929 5 Claims.

The present invention relates generally to mercury switches and more particularly the inven-= tion relates to mercury switches of the magnetic type in which the electrical connection between 5 the electrodes is made and broken by uniting and separating the mercury in the envelope, similar to those disclosed in my prior Patent Numher 1,861,630, granted June 7, 1932.

In the application referred to the core element of the electromagnet is situated in the mercury.

In switches of this type when the magnet is operating on alternating current the mercury is heated which increases the resistance of the mercury to limit the current carrying capacity of it the switch. In the switch of the foregoing application this difficulty is overcome by providing a large contact area for the mercury. The object of this invention is to entirely avoid this dimculty. The invention attains its object by 26 arranging the core of the electromagnet out of the mercury in the envelope of said device. In accordance with this object the envelope of the device is elongated to accommodate a plunger. Said plunger comprises a float member and a core oi. an electromagnet. Said float contains a body of mercury and is a chamber or cup made of an insulation material having suflicient buoyancy when immersed in mercury to support the core element of the magnet. Said core element 30 is mounted on and above said float chamber at all operating positions. The core element and the float chamber are guided in the envelope by one of the electrodes of the device. Said elec= trode makes contact with the mercury in the,

95 float chamber at all operating positions of said float and is in the longitudinal axis or said elongated envelope to keep the arc, caused by the breaking of the contact between the mercury pools, away from the walls of the envelope.

In the drawing accompanying and forming part of this specification two embodiments of the invention are shown, in which Fig. 1 is a sectional elevational view of one embodiment of the invention and Fig. 2 is a sectional elevational view of an alternative embodiment of the invention.

Like numbers denote like parts in both .fi res of the drawing.

Referring to Fig. 1 the invention comprises 50 an elongated envelope 1 having therein a mercury pool 9. Float 5 .is of insulation material,

such as glass, porcelain, etc., to electrically divide said mercury pool 9 irom-mercury pool 10 contained in said float 5 when plunger 5, 6 is 5 in its at rest position, in which position the connection between electrodes 2 and 3 is broken. Core 6 of electric-magnet 6, 7 is attached to float 5. Said float 5 is of sumcient buoyancy with respect to mercury pool 9 to support said core 6 and keep holes 8 above the level of said mercury pool 9. Float 5 has a thickened portion 4 to give additional buoyancy. Electrode 3 is immersed in mercury pool 9 and electrode 2 is immersed in mercury pool 10 at all positions of plunger 5, 6 and the electrode 2 serves as a guide for the vertical movements of said plunger 5, 6.

The new and novel switch of the present invention operates in the following manner. When plunger 5, 6 is in its at rest position electrodes 2 and 3 are electrically disconnected as herein- 79 before described. When coil 7 of the electromagnet 6, 'l is energized core 6 is attracted downward to the mid-point of said coil 7, guided thereto by electrode 2, forcing float 5 downward to displace the mercury in pool 9 so that the mercury pools 9 and 16 flow together through holes 8 to establish an electrical connection between electrodes 2 and 3 and current then flows through the switch. When coil '7 is short-circuited float 5 forces the plunger 5; 6 up, guided by electrode 80 2, to restore said plunger 5, 6 to its at rest position, in which position the connection between electrodes 2 and 3 is broken to interrupt the fiow of current through the switch.

The switch shown in Fig. 2 is in all respects 35 similar to that shown in Fig. 1 with the exception that in this case the buoyancy o! float 5 is insufllcient to support core 6 so that the two mercury pools 9 and 10 join through holes 8 when plunger 5, 6 is in its at rest position in which position electrodes 2 and 3 are electrically connected and current flows through the switch. When coil '7 is energized core 6 and therewith plunger 5, 6 is lifted up, guided by electrode 2, and the mercury in pool 9 is lowered until holes 8 are above the level of mercury pool 9 in which position off plunger 5, 6 themercury pools 9 and 10 are physically separated to break the electrical connection between electrodes 2, 3 interrupting the current flowing through the device. When coil '7 is short-circuited plunger 5, 6 falls back to its at rest position restoring the electrical connection between electrodes 2, 3 as hereinbefore described.

While I have shown and described a particular embodiment of my invention it will be understood that many substitutions, modifications, and changes in the form and details of the device and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention, for

example, electrode lead 2, used to guide the vertical movements of the plunger 5, 6 may be a thickened strongrod instead of a wire as shown,

float may be partly of metal and partly or I insulation material as desired, provided that part of float 5 dividing mercury pools 9 and 10 below the holes 8 is of insulation material.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A mercury switch comprising a container, electrodes sealed therein, a body of mercury therein, a plunger in said container, said plunger having a core out of said mercury at all operating positions of said plunger and adapted on successive movements thereof to make and break the electrical connection between said electrodes.

2. A mercury switch comprising a container,

electrodes sealed therein, a body of mercury therein, a plunger in said container, said plunger comprising a float and a core, said float supporting said core out of said mercury at alloperating positions of said plunger, said plunger being adapted on successive movements thereof to make and break the electrical connection between said electrodes.

3. A mercury switch comprising a container, electrodes sealed therein, a body of mercury therein, a plunger in said container, said plunger comprising a cup and a core, said core being out of said mercury in said container and above said cup at all operating positions of said plunger, said plunger being adapted on each successive movement thereofto break and make the electrical connectionbetween said electrodes.

4. A; mercury switch comprising a container, electrodes sealed therein, a body of mercury therein, a plunger in said container and above said cup at all operating positions of said plunger, one of said electrodes being adapted to guide said plunger at all operating positions of said plunger, said plunger being adapted on successive movements thereof to make and break the electrical connection between said electrodes.

5. A mercury switch comprising a container, electrodes sealed therein, a body of mercury therein, a plunger in said container, said plunger having a core out of said mercury at all operating positions oi said plunger, one of said electrodes being adapted to guide the vertical move-, ments of said plunger, said plunger being adapted on successive movements thereof to make and break the electrical connection between said 100 electrodes.

CHARLES HATAY. 

